Recording method and recording and reproducing apparatus for optical disk

ABSTRACT

A recording method and apparatus for an optical disk employs a data format having a fixed pattern sync portion in which a minimum run length of zeros and a maximum run length of zeros are not adjacent to each other. As such, temperature difference caused during recording the optical disk may be made smaller, thermal stress applied upon the medium may be reduced, the deterioration thereof may be restrained, and the repetitive frequency of the medium may be improved.

This application is a Divisional of application Ser. No. 08/118,353,filed Sep. 9, 1993, which is now U.S. Pat. No. 5,331,620, which in turnis a Continuation of application Ser. No. 07/651,618, filed Feb. 6, 1991and now abandoned.

BACKGROUND OF THE INVENTION

The present invention generally relates to a recording method for anoptical disk and a recording and reproducing apparatus, and moreparticularly, to a recording method and a recording and reproducingapparatus, which are capable of a rewriting operation, applying upon anoptical disk laser beams of approximately 1 micron in diameter,recording and reproducing signals of high density, and erasing oncerecorded signals by laser application, so that signals can be recordedand reproduced many times.

FIG. 9 (a) shows a block diagram of a recording system of theconventional optical disk recording and reproducing apparatus. Amodulating circuit 101 is adapted to modulate an input data 108 inaccordance with a modulation rule so as to output modulation data 109 inaccordance with a request from a selector 104.

A fixed pattern producing circuit 102 produces a fixed pattern FM 110 inaccordance with a request from the selector 104.

A synchronous signal producing circuit 103 produces a synchronous signalVFO 111 in accordance with a request from the selector 104.

The selector 104 combines the modulation data 109, the fixed pattern FM110, and the synchronous signal VFO 111 so as to output recording data112.

A laser driving circuit 105 drives the semiconductor laser 106 inaccordance with the recording data 112 to apply the recording data 112upon the optical disk 107, so that, for example, the reflection ratiovariation and so on are produced so as to effect the recordingoperation.

FIG. 9 (b) shows a block diagram of a reproduction system of theconventional optical disk recording and reproducing apparatus.

A weak laser power is applied to the optical disk 107 so as to obtain areproduction signal RF 118 through detecting the reflection light by anoptical detector 113.

A binary coded circuit 114 codes the reproducing signal RF 118 into abinary coded signal DSG 119.

A PLL circuit 115 generates a reproduction reference clock CLK 120 fromthe binary coded signal DSG 119.

A fixed pattern detecting circuit 116 detects a fixed pattern FM 110from the binary coded signal DSG 119 and the reproduction referenceclock CLK 120 so as to produce the detection signal FMD 121.

A demodulating circuit 117 demodulates the binary coded signal DSG 119from the reproduction reference clock CLK 120 and the detection signalFMD 121 so as to output the demodulation data.

FIG. 10 (a) shows a data format recorded on the optical disk by theconventional optical disk recording and reproducing apparatus. Therecording operation is effected in the order of a synchronous signalportion 44, a fixed pattern portion 45, a data 1 46a, a fixed patternportion 45, a data 2 46b, . . . , a fixed pattern portion 45, and a data46c, in succession subsequent to address portion 43 preformattedpreviously on the optical disk.

The synchronous signal VFO (FIG. 9, 111) is recorded on the synchronoussignal portion 44 for use in the locking of the PLL circuit (FIG. 9,115).

The fixed pattern FM (FIG. 9, 110) is normally recorded on the fixedpattern portion 45 so as to indicate the head of the data signal, and atthe same time is used to synchronize the data signal.

FIG. 10 (b) shows a concrete pattern 2-7-2-2 for the conventional fixedpattern FM (FIG. 9, 110) on the expression of (2-7) run-length-limitedcode as shown with D15 (Draft International Standard) 10089. Theconventional fixed pattern is constructed in the fixed pattern of2-7-2-2 in terms of the run length of zeros where the minimum run lengthof zeros 2 and the maximum run length of zeros 7 are adjacent to eachother, and the minimum run length of zeros 2 is adjacent to the otherminimum run length of zeros 2.

FIG. 10 (c) shows, for example, the modulation waveform of the laserwhen the conventional fixed pattern portion FM is actually recorded on aphase variation rewriting type optical disk. At the location of the data0, the erasing power (comparatively low power) is applied to erase theprevious data. At the location of the data 1, the recording power(comparatively high power) is applied so as to produce the recordingpits. The state of the recording pits is shown in FIG. 10 (d) .

SUMMARY OF THE INVENTION

Accordingly, the present invention has been developed with a view tosubstantially eliminating the above discussed drawbacks inherent in theprior art, and for its essential object to provide an improved datarecording method and a recording and reproducing apparatus.

Another important object of the present invention is to provide theimproved data recording method and recording and reproducing apparatuswhich restrains the repetition deterioration of the optical disk so asto improve the repetition frequency.

In accomplishing these and other objects, the present invention is arecording method for an optical disk which uses a data format having afixed pattern with the minimum run length of zeros and the maximum runlength of zeros not being adjacent to each other.

The temperature difference caused at the recording time on the opticaldisk may be made smaller, the thermal stress to be applied upon themedium is reduced, the deterioration is retrained, and the repetitionfrequency may be improved by the above described construction.

The present invention is a recording method for an optical disk whichuses a data format having a fixed pattern where the minimum run lengthof zeros is adjacent to the maximum run length of zeros, and the minimumrun length of zeros are not adjacent to each other.

By the above described construction, the temperature difference causedat the recording time on the optical disk may be made smaller, thethermal stress to be applied upon the medium may be reduced, thedeterioration may be restrained, and the repetition frequency may beimproved.

The present invention is a recording method for an optical diskcharacterized by the use of a data format having a fixed pattern portionconstructed through the selection of one data pattern at random for eachof the recordings from among a plurality of different data patterns.

By the above described construction, the probability of recording thesame fixed pattern for each of the recordings may be made smaller,thermal stresses may be prevented from being normally applied upon asmall location, and thermal stresses may be dispersed to prevent thedeterioration so as to improve the repetition frequency.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention willbecome apparent from the following description taken in conjunction withthe preferred embodiment thereof with reference to the accompanyingdrawings, in which;

FIG. 1 (a) is a block diagram of a recording system of a recording andreproducing apparatus for an optical disk in a first embodiment of thepresent invention;

FIG. 1 (b) is a block diagram of a reproducing system of a recording andreproducing apparatus for an optical disk in the first embodiment of thepresent invention;

FIG. 2 (a) is a block diagram of a data format for an optical disk inthe first embodiment of the present invention;

FIG. 2 (b) is a chart showing a fixed pattern in the first embodiment ofthe present invention;

FIG. 2 (c) is a chart showing the laser modulation waveform at the fixedpattern recording time in the first embodiment of the present invention;

FIG. 2 (d) is a chart showing the recording pits at the fixed patternrecording time in the first embodiment of the present invention;

FIG. 2 (e) is a chart showing the highest arrival temperature variationat the fixed pattern recording time in the first embodiment of thepresent invention;

FIG. 2 (f) is a block diagram showing the conventional fixed pattern;

FIG. 2 (g) is a chart showing a laser modulation waveform at theconventional fixed pattern recording time;

FIG. 2 (h) is a chart showing the recording pits at the conventionalfixed pattern recording time; and

FIG. 2 (i) is a chart showing the highest arrival temperature variationat the conventional fixed pattern recording time.

FIG. 3 (a) is a block diagram of a recording system of the recording andreproducing apparatus for an optical disk in a second embodiment of thepresent invention;

FIG. 3 (b) is a block diagram of a reproduction system of a recordingand reproducing apparatus for the optical disk in the second embodimentof the present invention;

FIG. 4 (a) is a block diagram of a data format for an optical disk inthe second embodiment of the present invention;

FIG. 4 (b) is a chart showing a fixed pattern in the second embodimentof the present invention;

FIG. 4 (c) is a chart showing the laser modulation waveform at the fixedpattern recording time of the second embodiment of the presentinvention;

FIG. 4 (d) shows the recording pits at the fixed pattern recording timein the second embodiment of the present invention;

FIG. 4 (e) is a chart showing the highest arrival temperature variationat the fixed pattern recording time in the second embodiment of thepresent invention;

FIG. 4 (f) is a block diagram showing the conventional fixed pattern;

FIG. 4 (g) is a chart showing a laser modulation waveform at theconventional fixed pattern recording time;

FIG. 4 (h) is a chart showing the recording pits at the conventionalfixed pattern recording time; and

FIG. 4 (i) is a chart showing the highest arrival temperature variationat the conventional fixed pattern recording time.

FIG. 5 (a) is a block diagram of a recording system of a recording andreproducing apparatus for an optical disk in a third embodiment of thepresent invention;

FIG. 5 (b) is a block diagram of a reproduction system of the recordingand reproducing apparatus for the optical disk in the third embodimentof the present invention;

FIG. 6 (a) is a block diagram of a data format for an optical disk in athird embodiment of the present invention;

FIG. 6 (b) is a chart showing a first fixed pattern in the thirdembodiment of the present invention;

FIG. 6 (c) is a chart showing the laser modulation waveform at the firstfixed pattern recording time in the third embodiment of the presentinvention;

FIG. 6 (d) is a chart showing the recording pits at a first fixedpattern recording time in the third embodiment of the present invention;

FIG. 6 (e) is a chart showing the highest arrival temperature variationat the first fixed pattern recording time in the third embodiment of thepresent invention;

FIG. 6 (f) is a block diagram showing the conventional fixed pattern;

FIG. 6 (g) is a chart showing a laser modulation waveform at theconventional fixed pattern recording time;

FIG. 6 (h) is a chart showing the recording pits at the conventionalfixed pattern recording time; and

FIG. 6 (i) is a chart showing the highest arrival temperature variationat the conventional fixed pattern recording time.

FIG. 7 (a) is a block diagram of a recording system of a recording andreproducing apparatus for an optical disk in a fourth embodiment of thepresent invention;

FIG. 7 (b) is a block diagram of a reproduction system of the recordingand reproducing apparatus for the optical disk in the fourth embodimentof the present invention;

FIG. 8 (a) is a block diagram of a data format for an optical disk in afourth embodiment of the present invention;

FIG. 8 (b) is a chart showing a first fixed pattern in the fourthembodiment of the present invention;

FIG. 8 (c) is a chart showing the laser modulation waveform at the firstfixed pattern recording time in the fourth embodiment of the presentinvention;

FIG. 8 (d) is a chart showing the recording pits at a first fixedpattern recording time in the fourth embodiment of the presentinvention;

FIG. 8 (e) is a chart showing the highest arrival temperature variationat the first fixed pattern recording time in the fourth embodiment ofthe present invention;

FIG. 8 (f) is a chart showing a second fixed pattern in the fourthembodiment of the present invention;

FIG. 8 (g) is a chart showing the laser modulation waveform at thesecond fixed pattern recording time in the fourth embodiment of thepresent invention;

FIG. 8 (h) is a chart showing the recording pits at the second fixedpattern recording time in the fourth embodiment of the presentinvention;

FIG. 8 (i) is a chart showing the highest arrival temperature variationat the second fixed pattern recording time in the fourth embodiment ofthe present invention;

FIG. 8 (j) is a chart showing a third fixed pattern in the fourthembodiment of the present invention;

FIG. 8 (k) is a chart showing a laser modulation waveform at the thirdfixed pattern recording time in the fourth embodiment of the presentinvention;

FIG. 8 (l) is a chart showing the recording pits at the third fixedpattern recording time in the fourth embodiment of the presentinvention;

FIG. 8 (m) is a chart showing the highest arrival temperature variationat the third fixed pattern recording time in the fourth embodiment ofthe present invention;

FIG. 9 (a) is a block diagram of a recording system of the conventionaloptical disk recording and reproducing apparatus;

FIG. 9 (b) is a block diagram of a reproducing system of theconventional optical disk recording and reproducing apparatus;

FIG. 10 (a) is a block diagram of a data format for the conventionaloptical disk;

FIG. 10 (b) is a block diagram showing the conventional fixed pattern;

FIG. 10 (c) is a chart showing a laser modulation waveform at theconventional fixed pattern recording time; and

FIG. 10 (d) is a chart showing the recording pits at the conventionalfixed pattern recording time.

DETAILED DESCRIPTION OF THE INVENTION

Before the description of the present invention proceeds, it is to benoted that like parts are designated by like reference numeralsthroughout the accompanying drawings.

The optical disk recording method and recording and reproducingapparatus in the embodiments of the present invention will be describedhereinafter.

Referring now to the drawings, there is shown in FIG. 1, a block diagramof a recording and reproducing apparatus for an optical disc in a firstembodiment of the present invention. FIG. 1 (a) shows a recordingsystem, and FIG. 1 (b) shows a reproducing system. It is to be notedthat like parts in the conventional embodiment of FIG. 9 are designatedby like reference numerals. The points which are different from those inthe conventional embodiment of FIG. 9 will be described hereinafter.

A fixed pattern FMA producing circuit 1 outputs a fixed pattern FMA 2.

A fixed pattern FMA detecting circuit 3 detects the fixed pattern FMA soas to output a detecting signal FMAD 4.

FIG. 2 (a) shows a data format to be recorded on an optical disc by arecording and reproducing apparatus for an optical disc in the firstembodiment of FIG. 1. The recording operation is effected in the orderof a synchronous signal portion 6, a fixed pattern portion 7, a data 18a, a fixed pattern portion 7, a data 2 8b, . . . a fixed patternportion 7, a data n 8c, followed by an address portion 5 address portion5 preformatted on the optical disc.

The synchronous signal VFO (FIG. 1, 111) is recorded on the abovedescribed synchronous signal portion 6 and is used for the lock of a PLLcircuit (FIG. 1, 115).

The fixed pattern FMA is normally recorded on the above described fixedpattern potion 7 to indicate the head of the data signal, and at thesame time, is used for synchronization with the data signal.

FIG. 2 (b) shows the concrete pattern of the fixed pattern FMA. Thepattern is the fixed pattern of 3-7-3-3 in the terms of the run lengthof zeros of (2,7) run-length-limited code with the maximum run length ofzeros 7 being not adjacent to the minimum run length of zeros 2.

FIG. 2 (c) shows the modulation waveform of the laser when, for example,the fixed pattern FMA of the present embodiment is actually recorded onan optical disc of the phase change rewriting type. In the locations ofthe data 0, the erasing power (comparatively low power) is applied so asto erase the previous data. In the locations of the data 1, therecording power (comparatively high power) is applied so as to generatethe recording bits. The recording bits are shown in FIG. 2 (d).

The conventional fixed pattern FM is shown in FIG. 2 (f) for comparison.FIG. 2 (g) shows the modulation wave form of the laser when theconventional fixed pattern FM is really recorded on the optical disc ofthe phase change rewriting type. In the locations where the data are 0,the erasing power (comparatively low power) is applied, and the previousdata are erased. In the locations where the data are 1, the recordingpower (comparatively high power) is applied so as to generate therecording bits. The recording bits are shown in FIG. 2 (h).

FIG. 2 (i) shows the highest arrival temperature change in the opticaldisc medium when the conventional fixed pattern FM is recorded. The Gpoint which is in the rear portion of a space 7 passes the comparativelylong period of time from the application of the recording power. The Hpoint which is in the rear portion of the space 2 passes only acomparatively short period of time from the application of the recordingpower, so that the highest arrival temperature T_(H) of the H pointbecomes higher than the highest arrival temperature T_(G) of the G point(T_(H) >T_(G)). As the I point which is the rear portion of the lastspace 2 of the conventional fixed pattern 2-7-2-2 passes only for ashort period of time after two time application for the short periodtime in the minimum run length of zeros 2, the highest arrivaltemperature T_(I) of the I point becomes much higher (T_(I) >T_(H)>T_(G)) than the highest arrival temperatures T_(G), T_(H) of the Gpoint, the H point. As the same fixed pattern FM is recorded for eachrecording, the temperature difference T_(H) -T_(G) between the G pointand the H point, and the temperature difference T_(I) -T_(G) between theG point and the I point are normally caused.

The highest arrival temperature change in the optical disc medium whenthe fixed pattern FMA of the present embodiment is shown in FIG. 2 (e).The fixed pattern FMA in the present embodiment is the fixed pattern of3-7-3-3 in terms of the run length of zeros. The A point which is in therear portion of the space 7 passes a comparatively long period of timeafter the application of the recording power. The B point which is inthe rear portion of the space 3 passes only a comparatively short periodof time than the A point from the application of the recording power, sothat the highest arrival temperature T_(B) of the B point becomes higherthan the highest arrival temperature T_(A) of the A point (T_(B)>T_(A)). The time elapsed from the application of the recording power inthe B point which is in the rear portion of the space 3 is longer thanthe elapsed time from the application of the recording power, in the Hpint in the rear portion of the space 2, within the conventional fixedpattern portion, so that the highest arrival temperature T_(B) of the Bpoint becomes lower than the highest arrival temperature T_(H) of the Hpoint (T_(H) >T_(B)). As a matter of fact it is lower than the highestarrival temperature T_(I) of the conventional I point (T_(I) >T_(H)>T_(B)). Although in the present embodiment, the temperature differenceT_(B) -T_(A) is caused at the fixed pattern FMA recording time in thepresent embodiment, the above described temperature difference T_(B)-T_(A) becomes smaller than the temperature difference T_(H) -T_(G),T_(I) -T_(G) to be caused at the conventional fixed pattern FM recordingtime.

According to the present embodiment, the fixed pattern is adapted sothat the minimum run length of zeros and the maximum run length of zerosare not adjacent each other, so that the temperature difference to becaused at the fixed pattern recording time may be made smaller thanbefore. The thermal stress to be applied upon the medium is reduced, thedeterioration of the medium is restrained, and the repetitive frequencymay be improved.

Although the case of (2,7) run-length-limited code has been described inthe present embodiment, the same effect may be obtained even in the caseof the other modulation code system (for example, (4, 15)run-length-limited code, and so on).

Although the description is given in a case where the fixed patternshows the head of the data signal, and is used for synchronization ofthe data signal in the present embodiment, the same effect may beobtained even in a case where it is used for an other object.

FIG. 3 shows the block diagram of the recording and reproducingapparatus of the optical disc in a second embodiment of the presentinvention. FIG. 3 (a) shows the recording system, and FIG. 3 (b) showsthe reproducing system. The same reference numerals are given to thesame parts as in the conventional embodiment of FIG. 9. The pointsdifferent from those in the conventional embodiment of FIG. 9 will bedescribed hereinafter.

The fixed pattern FMB producing circuit 9 outputs the fixed pattern FMB10.

The fixed pattern FMB detecting circuit 11 detects a fixed pattern FMBso as to output a detecting signal FMBD 12.

FIG. 4 (a) shows a data format to be recorded on the optical disc by therecording and reproducing apparatus for the optical disc in the secondembodiment of FIG. 3. The recording operation is effected in the orderof a synchronous signal portion 14, a fixed pattern portion 15, a data 116a, a fixed pattern portion 15, a data 2 16b, . . . a fixed patternportion 15, a data n 16c, followed by an address portion 13 preformattedon the optical disc.

The synchronous signal VFO (FIG. 3, 111) is recorded on the abovedescribed synchronous signal portion 14 and is used for the lock of aPLL circuit (FIG. 3, 115).

The fixed pattern FMB (FIG. 3, 10) is normally recorded on the abovedescribed fixed pattern potion 15 to indicate the head of the datasignal, and at the same time, is used for synchronization with the datasignal.

FIG. 4 (b) shows the concrete pattern of the fixed pattern FMB. Thepattern is the fixed pattern of 7-4-7 in terms of the run length ofzeros of (2,7) run-length-limited code with the maximum run length ofzeros 7 being not adjacent to the minimum run length of zeros 2. Also,the pattern of 7-4-7 is a violation code of the (2,7) run-length-limitedcode.

FIG. 4 (c) shows the modulation waveform of the laser when, for example,the fixed pattern FMB of the present embodiment is actually recorded onthe optical disc of the phase change rewriting type. In the locationswhere the data are 0, the erasing power (comparatively low power) isapplied so as to erase the previous data. In the locations where thedata are 1, the recording power (comparatively low power) is applied soas to generate the recording bits. The recording bits are shown in FIG.4 (d).

The conventional fixed pattern FM is shown in FIG. 4 (f) for comparison.FIG. 4 (g) shows the modulation wave form of the laser when theconventional fixed pattern FM is recorded on the optical disc of thephase change rewriting type. In the locations where the data are 0, theerasing power (comparatively low power) is applied, and the previousdata are erased. In the locations where the data are 1, the recordingpower (comparatively high power) is applied so as to generate therecording bits. The recording bits are shown in FIG. 4 (h).

FIG. 4 (i) shows the highest arrival temperature change in the opticaldisc medium when the conventional fixed pattern FM is recorded. The Gpoint which is in the rear portion of a space 7 passes the comparativelylong period of time from the application of the recording power. The Hpoint which is in the rear portion of the space 2 passes only acomparatively short period of time after the application of therecording power, so that the highest arrival temperature T_(H) of the Hpoint becomes higher than the highest arrival temperature T_(G) of the Gpoint (T_(H) >T_(G)). The I point which is in the rear portion of thelast space 2 of the conventional fixed pattern 2-7-2-2 passes only ashort period of time after two time application of the recording powerfor a short time period in the minimum run length of zeros 2, so thatthe highest arrival temperature T_(I) of I point becomes much higherthan the highest arrival temperatures T_(G), T_(H) of the G point, the Hpoint (T_(I) >T_(H) > T_(G)). As the same fixed pattern FM is recordedfor each recording, the temperature difference T_(H) -T_(G) between theG point and the H point, the temperature difference T_(I) -T_(G) betweenthe G point and the I point are normally caused.

The highest arrival temperature change in the optical disc medium whenthe fixed pattern FMB of the present embodiment is shown in FIG. 4 (e).The fixed pattern FMB in the present embodiment is the fixed pattern of7-4-7 in terms of the run length of zeros. The C point which is in therear portion of the space 7 passes a comparatively long period of timefrom the application of the recording power. As the D point which is inthe rear portion of the space 4 passes only comparatively shorter periodof time than the C point from the application of the recording power,the highest arrival temperature T_(D) of the D point becomes higher(T_(D) >T_(C)). As the time elapsed from the application of therecording power in the D point which is in the rear portion of the space4 is longer than the elapsed time from the application of the recordingpower, in the H point in the rear portion of the space 2, within theconventional fixed pattern FM, the highest arrival temperature T_(D) ofthe D point becomes lower than the highest arrival temperature T_(H) ofthe H point (T_(H) >T_(D)). As a matter of fact, it is lower than thehighest arrival temperature T_(I) of the conventional I point (T_(I)>T_(H) >T_(D) >). Although the temperature difference T_(D) -T_(C) iscaused at the fixed pattern FMB recording time in the presentembodiment, the above described temperature difference T_(D) -T_(C)becomes smaller than the temperature differences T_(H) -T_(G), T_(I)-T_(G) to be caused at the conventional fixed pattern FM recording time.

According to the present embodiment, the fixed pattern is the minimumrun length of zeros and the maximum run length of zeros are not adjacentto each other, so that the temperature difference to be caused at therecording time within the fixed pattern portion may be made smaller thanbefore. The thermal stress to be applied upon the medium is reduced, thedeterioration of the medium is restrained, and the repetitive frequencymay be improved.

Although the case of (2,7) run-length-limited code has been described inthe present embodiment, the same effect may be obtained even in the caseof the other modulation systems (for example, (4, 15) run-length-limitedcode, and so on).

Although the description is given in a case where the fixed patternshows the head of the data signal, is used for synchronization of thedata signal in the present embodiment, the same effect may be obtainedeven in a case where it is used for other object.

FIG. 5 shows the block diagram of the recording and reproducingapparatus for the optical disc in a third embodiment of the presentinvention. FIG. 5 (a) shows the recording system, and FIG. 5 (b) showsthe reproducing system. The points which are different from those in theconventional embodiment of FIG. 9 will be described hereinafter.

The fixed pattern FMC producing circuit 17 outputs the fixed pattern FMC18.

The fixed pattern FMC detecting circuit 19 detects a fixed pattern FMCso as to output a detecting signal FMCD 20.

FIG. 6 (a) shows a data format to be recorded on the optical disc by therecording and reproducing apparatus of the optical disc in the thirdembodiment of FIG. 5. The recording operation is effected in the orderof a synchronous signal portion 22, a fixed pattern portion 23, a data 124a, a fixed pattern portion 23, a data 2 24b, . . . a fixed patternportion 23, a data n 24c, followed by an address portion 21 preformattedon the optical disc.

The synchronous signal VFO (FIG. 5, 111) is recorded on the abovedescribed synchronous signal portion 22 and is used for the lock of aPLL circuit (FIG. 5, 115).

The fixed pattern FMC is normally recorded on the above described fixedpattern portion 23 to indicate the head of the data signal, and at thesame time, is used for synchronization with the data signal.

FIG. 6 (b) shows the concrete pattern of the fixed pattern FMC. Thepattern is the fixed pattern of 2-7-2-7 in the terms of the run lengthof zeros of (2,7) run-length-limited code with the maximum run length ofzeros 7 being adjacent to the minimum run length of zeros 2, but theminimum run length of zeros 2 is not adjacent to another minimum runlength of zeros 2. Also, the pattern 7-2 to be included in the 2-7-2-7pattern is a violation code of the (2,7) run-length-limited code. FIG. 6(c) shows the modulation waveform of the laser when, for example, thefixed pattern FMC of the present embodiment is actually recorded on theoptical disc of the phase change rewriting type. In the locations wherethe data are 0, the erasing power (comparatively low power) is appliedso as to erase the previous data. In the locations where the data are 1,the recording power (comparatively high power) is applied so as togenerate the recording bits. The recording bits are shown in FIG. 6 (d).

The conventional fixed pattern FM is shown in FIG. 6 (f) for comparison.FIG. 6 (g) shows the modulation wave form of the laser when theconventional fixed pattern FM is actually recorded on the optical discof the phase change rewriting type. In the locations where the data are0, the erasing power (comparatively low power) is applied, and theprevious data is erased. In the locations where the data are 1, therecording power (comparatively high bower) is applied so as to generatethe recording bits. The recording bits are shown in FIG. 6 (h).

FIG. 6 (i) shows the highest arrival temperature change in the opticaldisc medium when the conventional fixed pattern FM is recorded. The Gpoint which is in the rear portion of the space 7 passes a comparativelylong period of time from the application of the recording power. The Hpoint which is in the rear portion of the space 2 passes only acomparatively short period of time from the application of the recordingpower, so that the highest arrival temperature T_(H) of the H pointbecomes higher than the highest arrival temperature T_(G) of the G point(T_(H) >T_(G)). As the I point which is in the rear portion of the lastspace 2 of the conventional fixed pattern 2-7-2-2 passes only a shortperiod of time after two time application of the recording power for theshort time period in the minimum run length of zeros 2, the highestarrival temperature T_(I) of the I point becomes much higher than thehighest arrival temperatures T_(G), T_(H) of the G point, the H point(T_(I) >T_(H) >T_(G)). As the same fixed pattern FM is recorded for eachrecording, the temperature difference T_(H) -T_(G) between the G pointand the H point, the temperature difference T_(I) -T_(G) between the Gpoint and the I point are normally caused.

The highest arrival temperature change in the optical disc medium whenthe fixed pattern FMC of the present embodiment is shown in FIG. 6 (e).The fixed pattern FMC in the present embodiment is the fixed pattern of2-7-2-7 in terms of the run length of zeros. The E point which is in therear portion of the space 17 passes a comparatively long period of timefrom the application of the recording power. As the F point which is inthe rear portion of the space 2 passes only a comparatively shorterperiod time than the E point from the application of the recordingpower, the highest arrival temperature T_(F) of the F point becomeshigher than the highest arrival temperature T_(E) of the E point (T_(F)>T_(F)). But as the I point within the conventional fixed pattern FMpasses only a short period of time and after two time application of therecording power for a short period of time in the minimum run length ofzeros 2, the highest arrival temperature T_(I) becomes much higher thanthe highest arrival temperature T_(F) of the F point in the presentembodiment (T_(I) >T_(F)). In the present embodiment, the temperaturedifference T_(F) -T_(E) exists at the fixed pattern FMC recording time.The above described temperature difference T_(F) -T_(E) becomes smallerthan the temperature difference T_(I) -T_(G) to be caused at theconventional fixed pattern FM recording time.

According to the present embodiment, the fixed pattern is adapted theminimum run length of zeros and the maximum run length of zeros areadjacent each other, but minimum run length of zeros and another minimumrun length of zeros are not adjacent each other so that the temperaturedifference to be caused at the recording time within the fixed patternportion may be made smaller than before. The thermal stress to beapplied upon the medium is reduced, the deterioration of the medium isrestrained, and the repetitive frequency may be improved.

Although the case of (2,7) run-length-limited code has been described inthe present embodiment, the same effect may be obtained even in the caseof the other modulation system (for example, (4, 15) run-length-limitedcode, and so on).

Although the description is given in a case where the fixed patternindicates the head of the data signal, and is used for synchronizationof the data signal in the present embodiment, the same effect may beobtained even in a case where it is used for other objects.

FIG. 7 shows a block diagram of the recording and reproducing apparatusof the optical disc in a fourth embodiment of the present invention.FIG. 7 (a) shows the recording system, and FIG. 7 (b) shows thereproducing system. The points which are different from those in theconventional embodiment of FIG. 9 will be described hereinafter.

The fixed pattern FMD producing circuit 25 outputs the fixed pattern FMD28.

The fixed pattern FME producing circuit 26 outputs a fixed pattern FME29.

The fixed pattern FMF producing circuit 27 outputs a fixed pattern FMF(30).

It is to be noted that the fixed patterns FMD, FME, FMF are respectivelydifferent patterns. Concretely, the FMD are the patterns of 2-7-7 interms of the run length of zeros of the (2,7) run-length-limited code,the FME is a pattern of the 7-2-7, and the FMF is a pattern of the7-7-2.

The selector 31 selects and outputs one at random from the fixed patternFMD 28, the FME 29, and the FMF 30 when a request of the selector 104has been effected.

A fixed pattern FMD detecting circuit 32 detects the fixed pattern FMDso as to output the detecting signal FMDD 35.

A fixed pattern FME detecting circuit 33 detects the fixed pattern FMEso as to output a detecting signal FMED 36.

A fixed pattern FMF detecting circuit 34 detects a fixed pattern FMF soas to output a detecting signal FMFD 37.

An OR circuit 38 generates the OR of the detecting signals FMDD, FMED,FMFD as a detecting signal FMD' 121'. Therefore, if either of the fixedpatterns FMD, FME, FMF is detected, a detecting signal FMD' 121' isoutputted.

FIG. 8 (a) shows a data format to be recorded on the optical disc by therecording and reproducing apparatus for the optical disc in a fourthembodiment of FIG. 7. The recording operation is effected in the orderof a synchronous signal portion 40, a fixed pattern portion 41, a data 142a, a fixed pattern portion 41, a data 2 42b, . . . a fixed patternportion 41, a data n 42c, followed by an address portion 39 preformattedon the optical disc.

The synchronous signal VFO (FIG. 7, 111) is recorded on the abovedescribed synchronous signal portion 40 and is used for the lock of aPLL circuit (FIG. 7, 115).

A fixed pattern selected at random from the fixed patterns FMD, FME, FMFis recorded on the fixed pattern portion 41, indicates the head of thedata signal and at the same time, and is used for synchronization of thedata signal.

The fixed pattern portion when repetitive recording has been effectedwill be described hereinafter.

The concrete pattern of the fixed pattern portion at a first recordingtime will be shown in FIG. 8 (b). At this time, the pattern of FMD isselected, the fixed pattern of the 2-7-7 is recorded in the term of therun length of zeros of the (2,7) run-length-limited code.

The modulation waveform when a first fixed pattern FMD is recordedactually on the phase change rewriting type optical disc. In thelocations where the data are 0, the erasing power (comparatively lowpower) is applied so as to erase the previous data. In the locationswhere the data are 1, the erasing power (comparatively high power) isapplied so as to produce the recording bits. The recording bits areshown in FIG. 8 (d).

The highest arrival temperature distribution of the medium at the fixedpattern FMD recording time is shown in FIG. 8 (e). The front portion ofthe fixed pattern portion becomes higher at its average temperature asthe recording power is applied in the minimum run length of zeros 2. Themiddle portion and the rear portion thereof become lower at its averagetemperature than the front portion as the recording power is applied inthe space 7.

The concrete pattern of the fixed pattern portion at the secondrecording time will be shown in FIG. 8 (f). At this time, the pattern ofthe FME is selected, and the fixed pattern of the 7-2-7 is recorded interms of the run length of zeros of the (2,7) run-length-limited code.

The modulation waveform of the laser when the second fixed pattern FMEis actually recorded on the phase change rewriting type optical disc isshown in FIG. 8 (g). In the locations of the data 0, the erasing power(comparatively low power) is applied so as to erase the previous data.In the locations of the data 1, the recording power (comparatively highpower) is applied, and the recording bits are caused. The recording bitsare shown in FIG. 8 (h).

FIG. 8 (i) shows the highest arrival temperature distribution of themedium at the second fixed pattern FME recording time. At this time, theaverage temperature of the middle portion of the fixed pattern portionbecomes higher as the recording power is applied at the minimum runlength of zeros 2, and the front portion and the rear portion becomelower at the average temperature than the middle portion.

FIG. 8 (j) shows the concrete pattern of the fixed pattern portion at athird recording time. At this time, the pattern of the FMF is selected,and the fixed pattern of the 7-7-2 is recorded in terms of the runlength of zeros of the (2,7) run-length-limited code.

The modulation waveform of the laser when the third fixed pattern FMF isactually recorded on the phase change rewriting type optical disc isshown in FIG. 8 (k). In the locations of data 0, the erasing power(comparatively low power) is applied so as to erase the previous data.In the locations of the data 1, the recording power (comparatively highpower) is applied so as to produce the recording bits. The recordingbits are shown in FIG. 8 (l).

The highest arrival temperature distribution of the medium at the thirdfixed pattern FMF recording time is shown in FIG. 8 (m). At this time,the average temperature of the rear portion of the fixed pattern portionbecomes higher as the recording power is applied in the minimum runlength of zeros 2, and the average temperature between the front portionand the middle portion becomes lower than the rear portion.

According to the present embodiment, the probability becomes higher inthat the location where the temperature becomes higher changes for eachrecording operation into the front portion for the first time, themiddle portion for the second time, the rear portion for the third time.

In accordance with the present embodiment, by the selection andrecording of one fixed pattern at random from the different fixedpatterns for each of the recordings, the probability that the samelocation within the fixed pattern portion becomes normally higher intemperature becomes lower. As the thermal stress can be dispersed, thefatigue of the medium is reduced, thus making it possible to improve therepetitive frequency of the record reproduction.

Although the example of selecting from three types of fixed patterns hasbeen described in the present embodiment, the probability that the fixedpattern of the same pattern is recorded at each time becomes smallerthan before if the selection is effected from the fixed patterns of twotypes or more becomes smaller than before, so that a similar effect isobtained.

Although the case of the (2,7) run-length-limited code has beendescribed in the present embodiment, the similar effect may be obtainedeven in a case of the other modulation system (for example, the (4, 15)run-length-limited code and so on).

In the present embodiment, a case where the fixed pattern indicates headof the data signal, and is used for the synchronization of the datasignal is described, with a similar effect even in a case where it isused for other objects.

As the temperature difference to be normally caused at the recordingtime on the optical disk may be made as small as possible with the useof a data format having a fixed pattern portion which is composed of adata pattern where the minimum run length of zeros is not adjacent tothe maximum run length of zeros, the thermal stress to be applied uponthe medium is reduced, the deterioration is restrained, and therepetitive frequency is improved.

As the present invention uses the data format having the fixed patternportion composed of a data pattern where the minimum run length of zerosis adjacent to the maximum run length of zeros, but a minimum run lengthof zeros is not adjacent to another minimum run length of zeros, thetemperature difference to be normally caused at the recording time maybe made as small as possible, so that the thermal stress to be appliedupon the medium is reduced, the deterioration is restrained, and therepetitive frequency is improved.

The present invention uses a data format having a fixed pattern portioncomposed by the selection of one data pattern at random for eachrecording from a plurality of different data patterns, so that theprobability of recording the .same fixed patterns for each recordingbecomes smaller. As the thermal stress may be prevented from beingapplied upon the same location, the thermal stress is dispersed torestrain the deterioration and to improve the repetitive frequency.

Also, by the use of the data format having the fixed pattern portioncomposed of the data pattern where the minimum run length of zeros andthe maximum run length of zeros are adjacent to each other and theminimum run length of zeros are not adjacent to each other, thetemperature difference to be normally caused at the writing time may bemade smaller as much as possible, so that thermal stress to be appliedupon the medium is reduced, the deterioration thereof is restrained, therepetitive frequency is improved.

Also, by the use of the data format having the fixed pattern portioncomposed through selection of one data pattern for each recording atrandom from a plurality of different data patterns, the probability ofrecording the same fixed pattern is made smaller for each recording, thethermal stress may be prevented much as possible from being applied uponthe same location, so that the thermal stress is dispersed, thedeterioration is restrained, the repetitive frequency is improved.

Although the present invention has been fully described by way ofexample with reference to the accompanying drawings, it is to be notedhere that various changes and modifications will be apparent to thoseskilled in the art. Therefore, unless otherwise such changes andmodifications depart from the scope of the present invention, theyshould be construed as included therein.

What is claimed is:
 1. A method of generating optical disk recordingdata formed of successive one bits and zero bits having a run lengthlimited code data format in which at least a predetermined minimum runlength of recorded zero bits or at most a predetermined maximum runlength of zero bits is located on each side of recorded one bits, saidmethod comprising:generating a fixed pattern data frame used as asynchronous signal, the fixed pattern data frame having pluralsuccessive adjacent run lengths of zero bits with respective one bitslocated between each successive adjacent run lengths of zero bits andhaving at least three different run lengths of zero bits including atleast one of the minimum run length of zero bits and at least two of themaximum run lengths of zero bits; and, combining the fixed pattern dataframe with input data in accordance with the run length limited codedata format to generate the optical disk recording data; wherein, in theoptical disk recording data, an initial run length of zero bits of saidfixed pattern data frame is immediately preceded by a one bit and a lastrun length of zero bits of said fixed pattern data frame is immediatelyfollowed by a one bit, and wherein said fixed pattern data framecomprises two minimum run lengths of zero bits and two maximum runlengths of zero bits, wherein one of the two minimum run lengths of zerobits is located between the two maximum run lengths of zero bits, andwherein one of the two maximum run lengths of zero bits is locatedbetween the two minimum run lengths of zero bits.
 2. A method ofgenerating optical disk recording data formed of successive one bits andzero bits having a run length limited code data format in which at leasta predetermined minimum run length of recorded zero bits or at most apredetermined maximum run length of zero bits is located on each side ofrecorded one bits, said method comprising:generating a fixed patterndata frame used as a synchronous signal, the fixed pattern data framehaving plural successive adjacent run lengths of zero bits withrespective one bits located between each successive adjacent run lengthsof zero bits and having at least three different run lengths of zerobits including at least one of the minimum run length of zero bits andat least two of the maximum run lengths of zero bits; and, combining thefixed pattern data frame with input data in accordance with the runlength limited code data format to generate the optical disk recordingdata; wherein, in the optical disk recording data, an initial run lengthof zero bits of said fixed pattern data frame is immediately preceded bya one bit and a last run length of zero bits of said fixed pattern dataframe is immediately followed by a one bit, and wherein said fixedpattern data frame consists essentially of in succession a first minimumrun length of zero bits, a first one bit, a first maximum run length ofzero bits, a second one bit, a second minimum run length of zero bits, athird one bit, and a second maximum run length of zero bits.
 3. Anoptical disk recording apparatus for recording data formed of successiveone bits and zero bits having a run length limited code data format inwhich at least a predetermined minimum run length of zero bits or atmost a predetermined maximum run length of zero bits is located on eachside of recorded one bits, said apparatus comprising:recording datagenerating means for generating recording data in accordance with therun length limited code data format, the recording data including a dataportion and a fixed pattern data frame used as a synchronous signal, thefixed pattern data frame having plural successive adjacent run lengthsof zero bits with respective one bits located between each successiveadjacent run lengths of zero bits and having at least three differentrun lengths of zero bits including at least one of the minimum runlength of zero bits and at least two of the maximum run lengths of zerobits; and, recording means for recording the recording data on anoptical disk; wherein, in the recording data on the optical disk, aninitial run length of zero bits of said fixed pattern data frame isimmediately preceded by a one bit and a last run length of zero bits ofsaid fixed pattern data frame is immediately followed by a one bit, andwherein said fixed pattern data frame comprises two minimum run lengthsof zero bits and two maximum run lengths of zero bits, wherein one ofthe two minimum run lengths of zero bits is located between the twomaximum run lengths of zero bits, and wherein one of the two maximum runlengths of zero bits is located between the two minimum run lengths ofzero bits.
 4. A optical disk recording apparatus for recording dataformed of successive one bits and zero bits having a run length limitedcode data format in which at least a predetermined minimum run length ofzero bits or at most a predetermined maximum run length of zero bits islocated on each side of recorded one bits, said apparatuscomprising:recording data generating means for generating recording datain accordance with the run length limited code data format, therecording data including a data portion and a fixed pattern data frameused as a synchronous signal, the fixed pattern data frame having pluralsuccessive adjacent run lengths of zero bits with respective one bitslocated between each successive adjacent run lengths of zero bits andhaving at least three different run lengths of zero bits including atleast one of the minimum run length of zero bits and at least two of themaximum run lengths of zero bits; and, recording means for recording therecording data on an optical disk; wherein, in the recording data on theoptical disk, an initial run length of zero bits of said fixed patterndata frame is immediately preceded by a one bit and a last run length ofzero bits of said fixed pattern data frame is immediately followed by aone bit, and wherein said fixed pattern data frame consists essentiallyof in succession a first minimum run length of zero bits, a first onebit, a first maximum run length of zero bits, a second one bit, a secondminimum run length of zero bits, a third one bit, and a second maximumrun length of zero bits.